An indoor unit of an air conditioner is often disposed with a casing, which includes an outlet through which air is blown into a room, and a flap, which guides the air blown through the outlet. The flap is disposed so as to freely open and close the outlet, and is disposed so as to close the outlet in a closed state (Japanese Patent Publication No. 2003-130382, FIG. 1).
However, in the state where the flap closes the outlet, a borderline arises between the flap and the outlet. Conventionally, this borderline appears in the exterior of the indoor unit of the air conditioner and can easily be seen by the eyes of residents and the like in the room. For this reason, the borderline becomes design noise and results in marring the aesthetic look, such as lowering the interiority, of the indoor unit of the air conditioner.